"Don't touch a thing, the Tardis will get huffy if you mess"

First of all, that ending. Plenty of fans will have heads banging keyboards right now: the day was saved when a Big Friendly Button somehow rewrote time. I can't think of another story in Doctor Who history that makes fun of fandom so audaciously; things could only get more knowing if Diana Rigg's character in next week's episode turns out to be a ghost named Deus Ex Machina.

But wasn't it hilarious? Fans are always desperate for a glimpse of what lies beyond the Tardis's control room, so an episode set in her innards will always make us squeal.

In that sense, it's a sequel of sorts to The Doctor's Wife. Standing anything next to that tall poppy is a bit unfair, but even without Neil Gaiman and Suranne to power it, Journey holds its own. There's a little sub-genre developing here. Fans might remember with heavy heart The Invasion of Time from 1975, which realised the Tardis's vast expanses as a series of drab hospital corridors. Designer Michael Pickwoad did an admirable job of creating infinity with two weeks and a TV budget. It put me in mind of The Mind Robber.

And the ship's personality is developing nicely. From her wily ways back in the days of The Edge of Destruction through to last week, where she was described as "like a cat," she is probably the most consistent character in Doctor Who.

The fanboy left happy. Did you?

"Don't get into a spaceship with a madman: didn't anyone teach you that?"

Journey is kind of unusual for not having a villain. However it has zombies and a threat in the unknown depths of the Tardis. The closest thing to an antagonist is Gregor Van Baalen, the unscrupulous scavenger.

With another small cast, it's a credit to the writing and acting that their arc makes the story feel whole. The revelation of the Van Baalens – that Tricky is not an android but the third brother – gives the story an emotional wallop behind the fangasmic nature of the premise. As has often been the case this year, the characters are not hugely developed, but Gregor's manipulation of his kid brother has real notes of human tragedy. The guest stars sell it. And after the Big Friendly Button does its work there's a hint in the direction of their redemption.

To be fair, the Doctor saw them coming: Clara was in real danger, but his tricking of them into thinking that the Tardis was going to explode was too easy.

"I think I'm more scared of you than anything else on that Tardis right now"

Clara is a funny one this week. For half of the running time she's playing your generic damsel in distress and is understandably useless in that situation – well wouldn't you be? But not long later, she's dealing with the facts of her own mystery remarkably calmly. Probably she is just remarkable. There's been a lot of talk here and elsewhere that Clara hasn't yet become her own character. I would say that's unfair. Jenna-Lousie Coleman, who plays her, remains fantastic, and it's still early days.

Fear factor

For the third week running, the grounds on which this did best were the creepy ones. Director Mat King does a masterful job of giving the panicky, malfunctioning Tardis a real sense of menace. You're right there with Clara, however daft her predicaments get. And those ossified zombie monsters are horrific, even before we realise what they actually are. Job done.

Mysteries and questions

Frustratingly this episode advances the arc before striding right back to square one. Clara reads the Doctor's name in the Tardis library (what luck, it's on the first page she opens) and finds out about her multiple deaths, before the day-saving ways of the Big Friendly Button erase her memory. Still, we're approaching endgame and everything we look at has to be significant.

@HTPBDET came up with a great theory about a forgetful Doctor being the victim of companions being removed from his own past, but that was nixed by someone else pointing out how the comics are already doing a similar story.

On the subject of the 50th anniversary, @Branfish wondered if the existence of a Harvey as well as an Oswald on the asylum planet might be linked to another assassination that occurred in November 50 years ago. Me, I'm just wondering why, if nobody else survived the Timewar and the Doctor doesn't want anyone knowing his name, why is it mentioned in a book only he can have written?

Time-space debris

• The dialogue-echoes as Bran strips the Tardis console, date all the way back to Susan's speech from the very first episode, An Unearthly Child. How many other fragments of conversation did you spot?

• That first sequence in the Tardis is there to show off that this is the first set they've had that's completely 360 degrees – a shot they could never have done before.

• Second mention in as many weeks for the Eye of Harmony, a piece of Timelord engineering that manipulates black holes to fuel time travel. And this time we see the thing; with Gallifrey gone, it resides within the Tardis itself.

• A crack in time and an exploding Tardis both featured in Smith's debut series. Coincidence?

• Your suggestions as to the Doctor's real name, please …

Next week

It's the return of our favourite Victorian lesbian Siluran; and Madam Vastra and her Paternoster Gang lead their own investigation in Mark Gatiss's story The Crimson Horror.